1. Field of the Invention
The present invention relates to an active ray curable composition, an active ray curable ink composition for inkjet printing, an active ray curable adhesive composition, and a method for stabilizing an active ray curable composition.
2. Description of the Related Art
Active ray curable compositions are favorably used in applications such as compositions for inkjet printing, adhesive compositions, and resist materials.
Typical one of such active ray curable compositions is a combination of a radical reactive compound and a photoradical initiator. In this reaction system, although the reaction speed is high, the radials are immediately deactivated by oxygen and the reaction is terminated, making it difficult to completely eliminate the residual monomer.
Also, a reaction system employing a cation reactive compound and a photoacid generator in combination is known as one of the reaction systems that are not inhibited by oxygen. In this reaction system, the acid serving as a reactive species is not immediately deactivated, and thus, the reaction continues to proceed even after termination of light irradiation, resulting in that the residual monomer can be reduced. However, in general, the acid serving as a reactive species is a strong acid, which may disadvantageously corrode or modify a substrate.
In addition, there are a few reaction systems employing an anion reactive compound and a photobase generator in combination (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2005-060520). In these reaction systems, the reaction proceeds even by a weak base and thus, unlike the case of the cation reactive compound, corrosion does not arise. However, the reaction speed is very low, which is problematic.
In the above-described reaction systems, the photoradical initiator, the photoacid generator or the photobase generator decomposes to form reaction-initiating species, which may allow the reaction to proceed. Thus, a radical scavenger may be used as a polymerization inhibitor, a base may be added to an acid, or an acid may be added to a base (see, for example, Japanese Patent (JP-B) No. 3299513, JP-A No. 2002-285107, JP-B No. 4208414 and JP-A Nos. 2001-302881 and 2005-194357). However, there is a problem that these compounds inhibit the reaction after light irradiation.